Apparatus for etching.



J. PRIGGE.

APPARATUS FOR ETCHING.

APPLICATION HLEDJuNE26.1914.

PatentedSept 12,1916.

2 SHEETS-SHEET l Patented Sept. 12, 1916.

2 SHEETS-SHEET 2.

goa/m *71,27%

JOHANNES PRIGGE, OF MUNICH, GERMANY.

APPABATUS FOR ETCHING.

Specification of Letters Patent.

Patcnted Sept. 312, E118.

Application filed June 26, 1914. Serial No. 847,504.

Be it known that I, JouaNNns PRIGGE, a subject of the German Emperor, and resident of Munich, Germany, have invented certain new and useful mprovements in Apparatus for Etching, of which the following is a full and clear specification.

My invention relates in general to etching and more especially to that type of etching in which an etching fluid in finely divided form is thrown against the surface to be etched held at a suitable distance, so that the chemical effect is facilitated by the continuous wash of the etching fiuid against the surface.

According to the present invention the surface of the etching fluid is uniforinly broken up or finely divided by shaking or vibration and a definite air space is maintained between the surface of the fluid and the surface to be etched, so that the particles of the etching fluid which are'thrown out from the surface of the fluid pass through a body of air and impinge upon the surface to be etched. Care is taken that the surface of the etching fluid is always greater in eX- tcnt than the surface 'to be etched. An especially favorable result is obtained for the reason that the etching fluid is thrown heavily in more er less finely divided particles against the surface to be etched, and silnultaneously over its entirc extent, and because the maintenance of a definite air space between the surface of the fluid and the surface to bc etched gives rise to an' intimate mixture of the particles of the etching fluid with air, which is very beneficial to the chemical effect.

The accompanying drawing shows by way of example some embodiments of the apparatus for carrying out the etching, according to the present invention.

In said drawings, Figure 1 shows in elevation a simple etching device with movable 'i etching tray; Fi". 2 is a detail vertical section of a drive mechanism for the vibration of the baffles, independently of the tray; Fig. 3 is a seetional plan view of a combined etching and rinsing mechanism with movable baflles, taken on the line corresponding with A A of Fig. 2; Fig. 4 is a perspective view of an etching and rinsing apparatus in which several trays are disposed, one upon another.

Referring especially to Fig. 1, 1 indicates the etching tray which rests upon ecccentric or other vibrating drive means 2, 3, which drive means may be operated by gears 4 and 5, from the motor 6, whereby the tray 1 is given circular vibration in a horizontal plane, the eXtent of which is determined by the eccentricity of the drive 2 and 8. In the tray 1, there is built a cellular structure which, as shown in plan in Fig. 3, is preferably composed of thin Vertically disposed walls forming triangular compartments. These walls constitute the baflles or splashing devices. The plate S, which is to be etched, is in this form of the invention secured to a supporting arm 9, which can be adjusted up and down by means of the adjusting screw on the supporting post 11. Vith this arrangement, the plate 8, which is to be etched can be lowered from above and fixed at a given distance from the etching fiuid. Connected with the etching' tray 1 by means of the flexible tube 12 is the transparent fluid container 13, which rests upon a bracket 15 Vertically adjustable by means of the positioning screw 111. A scale 16 is fixed to the supporting arm 9, which scale is located adjacent the normal level of the fluid in the container 18 and has its zero point at the same level with the surface of the plate 8, which is to be etched, and thus shows the elevation of the plate. The entire device rests upon the frame 17, and the etchingl tray may be suitably inclosed in practice. In etching, the tray 1 is filled with the etching fluid almost up to the level of the upper surface of the splashers or bafiles 7. The plate S which is to be etched is then arranged at a suitable distance from the etching fluid, as determined by practice, with the aid of the positioning screw 10. As the fluid level in the container 13 is the same as that in tray 1 with which it communicates, the distance of the plate from the etching fluid can be directly observed upon the scale 1G, as its zero point shows the position of the plate. For effecting the etching operation the motor 6 is then started, so that-a circular vibration of the tray 1 in a horizontal pla-ne upon the drives 2 and 3 is set up. The 'fluid likewise vibrates in the same manner and impinges upon the baffles 7 which project somewhat above the surface, so that the fluid is uniformly broken up and splashed about over its entire surface. The small particles of fluid produced by this agitation are thrown violently against the plate 8, after they have the etchi had opportunity of mixing themselves thoroughly with the air on their way to the plate which to be etched, which is of great importance for the intensity of the etehing. nasmuch as the maintenance of a definite distance between the plate to be etched and the surface of the fluid is thus not only necessary for obtaining the splashing effect of the agitated and finely divided fluid against g surfac', as distinguished from a ierc wa 'ning, but is also necessary to secure e mixtrre of the finely divided fluid with air, this air space is always observed during the ctching process nd maintained at the proper magnitude as determined by experience, which can be done with the aid of the ineasuring vice 1(5 at the container 13, and by hydrostatic `Variation of the quantity of fluid in the tray 1, which latter is accomplished by raising or lowering the containei' as for example, by means of the positioning screw Simultaneously with this regulf'rtion of the air space, the level of the fluid in tray 1 can always be kept somewhat below the top of the baflles 7, which appear-s to be necessary for a breaking up of the fluid. it is, of course, apparent that the tray 1 may bc emptied by lowering the con tainer 13 to the necessary extent. An especially effective breaking up of the fluid over its entire surface can be obtained. by an apparatus in which the bailes may be given circular vibration in a horizontal plane while the tray itself remains at rest. This arrangement has further the special advantage that the masses necessary to be moved are mach less than. in the first described construction of the device.

Fig. 2 shows in vertical section a part of an etching tray with a splashing member which is independently moved by means of a special device. The fluid lever regulating device above described is understood to be employed in connection with the form of apparatus herein shown. The etching ti'ay is indicated at 18, and in this tray the splasher 19 is again arranged as before, with the fluid level 20 slightly below the top the splasher. The frame f of plate 8 to be etched is supported at either side on track or ledge 25 of suitable material. The splasher is formed of baflle plates which may be arranged in the same manner as already shown in Figs. l and 3, except that they are movable indcpendently of the tray 18, which latter is held stationary. The operating device for the splasher shown in Fig. 2 is made of such construction that it can not be destroyed by the etching fluid and that a good lubrication of the moving parts is ale. ays possible without the lubricating material being able to get into the etching fluid. The splasher 19 is provided with a nose-like projection 21 in which a pin 22 engages, which is eccentrically seated in a disk 23.

The disk 23 is secured upon the lower end of a shaft 25 which is surrounded by a bearing sleeve 24, which shaft has a gear wheel 2G fixed on its upper end. The gear wheel 26 engages with a gear wheel 28, which is loose upon shaft 27. This shaft 27 is driven from any suitable source of power. A clutch disk 29, provided with a locking pin 30 is slidably positioned in known manner upon the shaft 27. The shaft 27 can be coupled thereby with the drive wheel 28, as when shifted, the locking pin 30 is brought into engagement with the nose 31. In order to protect those parts of the drive mechanism which are in the neighborhood of the etching fluid from its attack, a beaker-like vessel 32 of acid-proof material is coupled with the disk 23, so that it rotates therewith and incloses the sleeve 24 and Shaft 25, thus keeping'them out of contact with the etching fluid. This vessel 32 is filled with lubricating material, such as oil, which'creeps into the bearing sleeve at the bottom by capillary attraction and hydrostatic pressure, so that the shaft is always well lubricated. Between the cover plate 33 and the wall of the tray 18 there is disposed an inclosing cylindrical she-el ;Elof glass, for example. The `Yertical supports or shafts 25 and 27 do not constitute features of novelty in my present invention and hence are omitted from the drawing. It will be understood that one of these driving arrangements is arrangcd on each side of the splashers 19. By connecting the gear wheel 28 with the driven shaft 27, the disk 23, which carries the cc' centric pin 22 is rotated through the gear 2G and shaft 25, whereby the splasher 19 is given a circular vib'ation. The arrangement of the splashersiso that they may be vibrated independently of the tray, afi'ords a simple construction of the entire etchi device and makes possible directly the combination of an etching device with a rinsing device and beside this a compact and hygienic grouping of several etching devices in unit form.

Fig. 3 represents in sectional plan a combined etching and rinsing device taken on a level corresponding with line ;irof Fig. 2. The tray 35 may be regarded as the etching tray, while the tray 36 serves as the rinsing tray. In both trays there are disposed the cellular splashing devices 37 and 38, which are capable of circular vibration in lioi'iL-'mital plane, independently of the trays themselves. These splashing devices are vibrated, for example, by driving mechanism, such as shown in Fig. 2, which engages them by the nose-like projections 39, ylO, or 41, 42, respectively. A common housing 13 incloses the two trays, which are separated from each other by fluid dfiains all. The fluid level, especially in the etchiug tray, may, as before, be regulated hydrostatically ,mam

by means of a movably arranged fiuid container, which communicates With the tray. This device is not illustrated in Fig. 8. The housing 43 has at the side of the rinsing tray an opening 45, through which a carrier in the form of a frame for the plate to be etched can be introduced and removed. For etching, this frame is passed through the narrow opening 15, over the rinsirig tray 3G to the etching tray 35. After the etching has been completed, the frame is drawn back to the rinsing tray 36, where the rinsing can be accomplishcd, whereupon'the frame With the completely e-tched and Washed plate is taken out of the device. The different driving devices for the splashers 37 and 38 should in this arrangement be capable of being connected together in pairs, as shown for example in Fig. l and hereinafter described, with a common drive. The fluid drains al are arranged so that the fluid splashed from one tray can not get into the other. These drains communicate preferably with the trays adj acent to them, so that the fluid collected in them will be returned to the tray from which it escapes. It will be obvious that in this combination of an etching tray with a rinsing tray, the process is especially simple. The etched plate can be rapidly brought from the etching tray to the rinsing tray and there washed, so that all danger of oXidation is avoided. The plates also do not come out of the device with etching` fluid on them. Furthermore, the escape of the etching fluid vapor into the surrounding room is practically obviated, which is of considerable importance from a hygienic standpoint. 'A combined etching and rinsing apparatus of this type can be built up in unit form with the parts one over another, as shown in perspective in Fig. 4.

In Fig. l, lG and '-.l7 are two trays, each of whicli contains etching and rinsing devices, such as shown in Fig. 3. The individual units of the trays can be operated by the common drive shafts -LlS and -'l9, which correspond with similar parts on the other side of the apparatus, not visible in Fig. l. These shafts '-lS, -l9 and the parts operated thereby7 can be selectively thrown into and out of operation, as the respective couplings or of, are shifted in or out by the coupling rods 50 and 51. This clutching mechanism, as will be apparent from the drawing, is so arranged with each of the rods 50 and 51 pivoted midway between the clutclies for its etching tray and washing tray that the clutch for the rinsing tray will be thrown out simultaneously with the throwing in of the clutch for the etching tray. All the driving mechanism for the several trays is supplied with power from a common power source, such as, for example, 'a motor 5G. Any number of trays desired can obviously bearranged one over another as shown. On each tier or level, one plate is inserted and completely etched and washed and then withdrawn before another is inserted. lt will be understood that the plate is introduced and withdrawn at the same side, through one of the openings 57 or 58. The narrow openings 57 and 58 serve for introducing and withdrawing the frames for the plates which are to be etched, the frames f containing t ie plates 8, sliding in and out upon the tracks or ledges (see Fig. 2).

' ln order to insure that there will always' be sullicient fresh air for mixture With the finely divided etching fluid, a special air supply can be provided for any or all of the described forms of the invention, which, for example, may comprise an air pump, which delivers the air through a pipe into the etching tray, while the used air is withdrawn through another pipe.

In the operation ofv the apparatus, according to my invention, the etching fluid is broken up into more or less i'inely divided form. It is not however the intention or the fact that the ctching fluid is atomized.

I claim:

1. Apparatus of the character described, comprising in combination a tray for the etching` fluid, baflles therein to serve asv splasher devices, means for supporting the article to be etched above the liquid in said tray and means for vibrating said baflies to finely divide and project the etching fluid against the article to be etched in a direction substantially normal thereto.

2. rlpparatus of the character described, comprising in combination a tray for the etching fluid, vertically disposed intersecting baffles subdividing` said tray into compartments, means for supporting` the article to be etched above said tray and means for eifecting a circular vibration said baflles in a horizontal plane, to splash the etching fluid substantially vertically against the article to be etched.

3. Apparatus of the character described, comprising in combination a tray for the etching fiuid, vertically disposed intersecting baflles subdividing said tray into triangular compartments, means for supporting the article to be etched above said tray and means for effecting a circular vibration of said baffles in a horizontal plane, to splash the etching fluid substantially vertically against the article to be etched.

a. Apparatus of the character described,

com orisin in combination a tra for the etching` fiuid, baflles therein to serve as splash devices, means for supporting the article to be etched above the liquid in said tray, means for supplying etching fluid to said tray and automatically correlating the level thereof to the position of said article to be etched, and means for vibrating said balfles to Splash the etching fluid against the article to'be etched.

5. Apparatus of theeharacter described, comprising in combination a tray for the etehing fluid, adj'ustable means for maintaining etching fluid therein at a desired level, adjustable means for supporting an article to be etched at a desired elevation above the level of the etching fluid in said tray with an air space between, baffies immersed in the etehing fluid contained in said tray, and means for vibrating said baflles to Splash the etchng fiuid through the air space against the article to be etched.

6. Apparatus of the character described, comprising in combination a tray for the etching fiuid, baffles disposed therein and movable with respect thereto, means for supporting the article to be etched above the liquid in said tray, and means for vibrating said baflles independently of said tray, to finely divide and project the etching fluid substantially vertically against the article to be etched.

7. Apparatus of the character described,

comprising in combination a tray for the etching fluid, a tray for the rinsing` fiuid, ballles disposed in each of 'said trays, means for vibrating said baflles in the etching and rinsing trays to effect a splashing of the fiuids contained therein, and means permitting the insertion and Withdrawal of an article to be etched across the space over said etching` and rinsing trays.

8. Apparatus of the character desc'ribed, comprising in combination a tray for etching fluid, ball'les disposed therein and movable independently thereof, an eccentric mechanism for vibrating said ball'les, and an acid-proof vessel inclosing said eccentric mechanism for supplying lubricating material thereto and excluding the ctching fluid 9. Apparatus of the character described, comprising in combination a tray, bal'lles therein to serve as Splash devices, means for vibrating said balfles, means for supplying fluid to said tray, comprising a fluid container and a supply pipe communicating With said tray and adapted to maintain hydrostatic equilibrium between bodies of liquidv in the tray and in the container, said flnld lcontainer having adjustable elevating means, and means for supporting an article oto be etched above the liquid in said tray.

for adjusting the elevation of said article, a

seale indicating said elevation, means 'for' vibrating said baffles, a transparent container for fiuid, having a supply pipe c0mmunieating With saidV tray, and means for raising and lowering said transparent container adjacent to said Scale for correlating the fluid level with the elevation of the article to be etched.

11. Apparatus'of the character described, comprising in combination Van etching tray, a rinsing tray, baflies disposed therein, means for 'supplying etching and rinsing fiuids respectively to said trays, means for vibrating said baffles, and a common housing inclosing` said trays having an opening permitting the insertion and withdrawal of an article to be etched across said rinsing tray to and from said etching tray.

12. Apparatus of the character deseribed, comprising in combination a plurality of units disposed one above another, each comprising etching and rinsing apparatus With vibratory bafl'les constituting splash devices, driving mechanism for the individual Splash devices, individual clutching mechanism for said driving` devices, and a common power supply for all of said driving devices.

13. Apparatus of the character described,

comprising in combination a tray for thev etc-hing fluid, bafl'les therein to serve as spasher devices, means for supporting the article to be etched above the liquid in said tray, Whereby an air gap is maintained between them, and means for vibrating said ballles to finely divide and project the etching fluid con'imingled With air against the article to be etched, in a direction substantially normal to the surface of said article. J OHANNES PRIGG'E. 7itnesses A. LEIFFMANN, 7. ELD.

Copies of this patent may be obtained for five cents each, by addressing the Commissoner of Patents. Washington, D. C." 

